Bug report
Bug description:
This loop can run forever if there's a cycle in the Makefile variable definitions:
| while len(variables) > 0: |
To reproduce:
make clean echo 'foo=$(foo)' > ./Modules/Setup.local ./configure make # hangs forever
Or more minimally:
make clean echo 'foo=$(foo)' > ./Modules/Setup.local make Makefile ./python -m sysconfig --generate-posix-vars # hangs forever
Longer cycles are also possible, e.g. v1=$(v2), v2=$(v3), ...., v999=$(v1).
Note that this is less of an issue if the recursive variable definition gets expanded in the Makefile before python -m sysconfig --generate-posix-vars gets invoked. In that case, Make will detect the cycle and exit before the infinite loop occurs.
@serhiy-storchaka you may be interested, this is very similar to #136073
CPython versions tested on:
CPython main branch
Operating systems tested on:
Linux